1. Field of the Invention
The present invention relates to a mobile communication terminal configured to switch a call path to another, and to a call handover method.
2. Description of the Related Art
There has been heretofore proposed a technique that allows a mobile telephone terminal to stably communicate with a fixed-line telephone terminal by connecting the mobile telephone terminal to the fixed-line telephone terminal through a wire. This technique also allows a destination of the charge for such a call to be selected when an appropriate pin number is inputted to the mobile telephone terminal.
Furthermore, through advances in a short-range wireless communication technology such as Bluetooth (registered trademark), a communication service called, fixed mobile convergence (FMC) has been attracting attention. In this communication service, a mobile telephone terminal is wirelessly connected to a fixed-line telephone terminal and then is used as a cordless handset in the house.
According to the FMC, a mobile telephone terminal performs communications using a mobile telephone terminal network when the mobile telephone terminal is located outside the house, and performs communications using a fixed-line telephone network when the mobile telephone terminal is located in the house. Since the mobile telephone terminal performs communications using the fixed-line telephone network when the mobile telephone terminal is located in the house, the costs of the call can be reduced or the communication speed can be increased.
Here, a switching (hereinafter, termed as a “call handover”) from a mobile telephone network to a fixed-line telephone network while retailing a call without disconnection is required in a case where a user moves to the inside of the house from the outside of the house during a call being made using a mobile telephone network. In order to achieve such a call handover, however, the aforementioned FMC needs constructing a dedicated system in a communication network. Moreover, in the FMC, the mobile telephone terminal and the fixed-line telephone terminal need to use the same telephone company and the same telephone number. For this reason, when an existing communication network is used, it is difficult to perform a call handover between a mobile telephone network and a fixed-line telephone network while retaining a call without disconnection.